// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_BROWSER_LOADER_THROTTLING_RESOURCE_HANDLER_H_
#define CONTENT_BROWSER_LOADER_THROTTLING_RESOURCE_HANDLER_H_

#include <stddef.h>

#include <memory>
#include <vector>

#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "content/browser/loader/layered_resource_handler.h"
#include "content/common/content_export.h"
#include "content/public/browser/resource_throttle.h"
#include "net/url_request/redirect_info.h"
#include "url/gurl.h"

namespace net {
class URLRequest;
}

namespace content {

struct ResourceResponse;

// Used to apply a list of ResourceThrottle instances to an URLRequest.
class CONTENT_EXPORT ThrottlingResourceHandler
    : public LayeredResourceHandler,
      public ResourceThrottle::Delegate {
public:
    ThrottlingResourceHandler(
        std::unique_ptr<ResourceHandler> next_handler,
        net::URLRequest* request,
        std::vector<std::unique_ptr<ResourceThrottle>> throttles);
    ~ThrottlingResourceHandler() override;

    // LayeredResourceHandler overrides:
    bool OnRequestRedirected(const net::RedirectInfo& redirect_info,
        ResourceResponse* response,
        bool* defer) override;
    bool OnResponseStarted(ResourceResponse* response, bool* defer) override;
    bool OnWillStart(const GURL& url, bool* defer) override;

    // ResourceThrottle::Delegate implementation:
    void Cancel() override;
    void CancelAndIgnore() override;
    void CancelWithError(int error_code) override;
    void Resume() override;

private:
    void ResumeStart();
    void ResumeRedirect();
    void ResumeResponse();

    // Called when the throttle at |throttle_index| defers a request.  Logs the
    // name of the throttle that delayed the request.
    void OnRequestDeferred(int throttle_index);

    enum DeferredStage {
        DEFERRED_NONE,
        DEFERRED_START,
        DEFERRED_REDIRECT,
        DEFERRED_RESPONSE
    };
    DeferredStage deferred_stage_;

    std::vector<std::unique_ptr<ResourceThrottle>> throttles_;
    size_t next_index_;

    GURL deferred_url_;
    net::RedirectInfo deferred_redirect_;
    scoped_refptr<ResourceResponse> deferred_response_;

    bool cancelled_by_resource_throttle_;

    DISALLOW_COPY_AND_ASSIGN(ThrottlingResourceHandler);
};

} // namespace content

#endif // CONTENT_BROWSER_LOADER_THROTTLING_RESOURCE_HANDLER_H_
